阿摩線上測驗
11. Which valve is used to prevent return or back-flow in pipe-lines and is automatically
operated?
(A) Check and stop valve
(B) Gate valve
(C) Globe valve
(D) Angle valve
答案：登入後查看
統計： A(112), B(15), C(15), D(7), E(0) #3171830
統計： A(112), B(15), C(15), D(7), E(0) #3171830
